1. Field of the Invention
The present invention relates to an improvement of a call signal conversion apparatus for an elevator system.
2. Description of the Prior Arts
The elevator system equipped with digital apparatus such as a computer need to have floor buttons and car buttons and registration lamps which are connected with the buttons to turn-on by each calling and a signal conversion circuit for converting signal to a control device of the computer.
Heretofore, the signal conversion circuit usually comprises independently a signal conversion circuit for call buttons and a signal conversion circuit for registration lamps as shown in FIG. 1.
In FIG. 1, the reference numeral (1) designates a call button; (2) designates an elevator control device; (3) designates a call button signal conversion circuit; (4) designates a call registration lamp; and (5) designates a call registration lamp signal conversion circuit. The call button signal conversion circuit (3) comprises a detection circuit for detecting the call signal resulted by the actuation of the call button (1); a conversion circuit for converting the signal required for transmitting the detected signal to the control device (2); and a logic circuit for transmitting and controlling the call data to the control device (2) depending upon the desired data command time given by the control device (2). In the control device (2) receiving the data from the call button signal conversion circuit (3), the calling is memorized (registered) and a turn-on command is transmitted to the call registration lamp signal conversion circuit (5) so as to turn-on the corresponding call registration lamp (4). The signal conversion circuit (5) comprises a logic circuit which controls the turn-on of the call registration lamp (4) by receiving the command from the control device (2) and a driving circuit which is actuated by the logic circuit so as to turn-on the call registration lamp (4) by the output of the driving circuit.
As mentioned above, the conversion circuit (3) and the conversion circuit (5) are the separate circuits whereby they can be also utilized as the other device such as a relay driving circuit and a position indicator driving circuit. However, the number of the relays is reduced depending upon the development of the control device (2) with semiconductors, though many relays had been used. Moreover, only the signal conversion circuits for service floors are needed for the position indicators. Therefore, the ratio of the signal conversion circuits for calling in the elevator system has been increased. In the conventional apparatus, the signal conversion circuit (3) for the button (1) and the signal conversion circuit (5) for the call registration lamp (4) have been separately needed, to cause useless circuit equipments. The number of the print boards has been increased to cause high cost for the signal conversions.
As signal lines from the call buttons to the elevator control panel, one line is needed for detecting the calling and one line in needed for turning on the call registration lamp. Three kinds of callings as the car call, the floor uphall call and downhall call are given. Therefore, six signal lines are needed for one floor. The number of the lines is increased in proportional to the number of the elevator service floors, whereby the cost and processes for construction are disadvantageously increased.